Steam-engine.



B. H. KNAPP.

STEAM ENGINE. APPILIOATIOK FILED JUNE 10. 1907.

PATENTED JUNE 2, 1908.

s SHEETS-SHEET 1.

INVENTOR No. 889,622. PATENTED JUNE 2-, 1908,

E. KNAPP; STEAM ENGINE r cum LED JUN so A Pu H E 1 'l QSHBETS-SHEET a.

--1 a r- 2- '1 1 I i l WI lulu. 42 a? PATENTBD JUNE 2, 1908.

ERVIN HARM KNAPP, OF GODDARD, KENTUCKY.

STE AM-ENGINE Specification of Letters Patent.

Patented June 2, 1908.

Application filed June 10, 1907. Serial No.-378,677.

T 0 all whom it may concern:

Be it known that I, ERVIN HARM KNAPP, a citizen of the United States,residing at Goddard, in the county of Fleming and State of Kentucky,have invented certain new and useful Improvements in Steam-Engines; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to new and useful improvements in engines, and moreparticularly to that class adapted to be operated by steam and my objectis to provide means for increasing the driving capacity of the engineswithout materially increasing the size of the cylinder.

A further object is to provide means for employing the expanded steam aswell as live steam for driving the pistons, and a still further objectis to provide means for starting the engine when the crank, and partscar- .ried thereby, are on a deadcenter.

Other objects and advantages will be hereinafter referred to and moreparticularly pointed out in the claims.

In the accompanying drawings which are made a part of this application,Figure 1 is a top plan view of my improved form of engine, showing thevalve chest in section. Fig. 2 is a top plan view of the cylinderportion of the engine, showing the chest and valves therein removed.Fig. 3 is a sectional View as seen on line 3-3, Fig. 2. Fig. 4 is asectional view through one of the pistons. Fig. 5 is a longitudinal,sectional View through the engine showing the same on its rearwardstroke. Fig. 6 is a detail, sectional view through the auxiliary valvechest with the parts thereof in the position when the pistons are ontheir rearward stroke. Fig. 7 is a central, sectional view throu h theengine, showing the pistons on their 'orward stroke. Fig. 8 is a detail,sectional view through the auxiliary valve chest showing the position ofthe parts thereof when the pistons are on their forward stroke. Fig. 9is a central, sectional View through the engine, showing the position ofthe parts thereof when the crank is at a dead center. Fig. 10 is adetail, sectional view through the auxiliary valve chest showing the,position of the parts thereof when the crank of the engine is on a deadcenter, and, Fig. 11 is a detail, plan view of the pistons removed fromthe cylinder.

Referring to the drawings in which similar reference numerals designatecorresponding parts throughout the several views, 1 indicates the baseof my improved engine, which may be constructed in the usual, or anypreferred form, upon which is mounted a cylinder 2, to each end of whichis secured a head 3, said heads being extended below the cylinder 2 toform supports 4, said supports resting on the base 1 and being securedthereto in any preferred manner.

Rotatably mounted in bearings 5 at the forward end of the base 1 is adriving shaft 6, that portion of the shaft 6, between the bearings 5,being provided with cranks 7 and 8,

While the ends of the shaft are extended beyond the bearings 5 toreceive a pulley 9 at one end, and a power wheel 10 at the opposite end.

Secured at one end to the cranks 7 and 8 are arms 11 and 12,respectively, the opposite ends of said arms being pivotally connectedto piston shafts 13 and 14, respectively, said piston shafts extendingthrough openings in one end of the cylinder 2 and parallel with eachother. The piston shaft 13 has fixed thereto a pair of pistons 15 and16, the piston 16 being fixed to the extreme inner end of the shaft 13,while the piston 15 is at a .distance therefrom and is provided with abearing, through which the shaft 14 is adapted to reciprocate. The shaft14 is of less length than the shaft 13 and is so arranged that the innerend thereof will always remain betweenthe pistons 15 and 16, a piston 17being fixed to theinner end of the piston 14 and provided with a bearing18, through which the shaft 13 reciprocates, the bearings in the pistons15 and 17 having the usual, or any preferred form of packing 19, toprevent leakage of steam through the pistons.

The cranks 7 and 8 rest at difierent angles,

and are at an angle of substantially 45 from each other, so that whenthe pistons 15 and 16 are traveling in one direction, the piston 17 istraveling in the opposite direction, the pistons 15 and 16 beingseparated a sufficient distance to allow the piston 17 to make its fullstroke, and by properly directing the steam into the cylinder, pressuremaybe applied simultaneously to the two pistons 15 and 16 to drive themin one direction and to the piston 17 to drive the same in the oppositedirection, thereby causing one of the arms to pull upon its respectivecrank, while the opposite arm is giving a thrust to the opposite crank,thereby increasing or cloubling the driving capacity of the enginewithout increasing the cylinder space or employing more than onecylinder.

In directing live steam into the cylinder, a

' steam chest 20 is mounted above the cylinder,

and that portion of the cylinder inclosed by the steam chest isflattened to form a seat 21 for a steam valve 22, said valve having apitman 23 pivotally secured to the upper surface thereof and extendedthrough the usual form of stuffing box at one end of the being locatedat opposite ends of the steam chest and are so arranged that when one of1 the ports is open, the opposite port is closed by the valve 22 and thepistons 15 and 16 are arranged to travel between their respective portsand the ends of the cylinder, while the piston 17 is adapted to travelbetween the two ports, and as shown in Figs. 5 and 7, when the livesteam is entered into the cylinder, it passes between one of the end pistons of the intermediate piston, thereby driving said pistons inopposite directions.

In Fig. 5 of the drawings, the live steam is entering through the port27 and between the pistons 16 and 17, thereby driving the pistons 15 and16 towards the rear end of cylinder, while the piston 17 is driven inthe opposite direction, thereby causing the arm 11 to pull upon itsrespective crank 7, while the arm 12 is given a forward thrust, and thusdriving the crank 8. At the same time that the live steam is enteringbetween the pistons 16 and 17, the expanded steam between the pistons 15and 17 will pass through a port 28, through the seat 21, and into acavity 29 formed in the lower face of the valve 22, a bar 30 beingextended from side to side of the valve so that the expanded steam, inits course through the cavity will pass over the bar 30 to gain theopposite end of the cavity, and in order to utilize the expanded steamin operating the pistons, an auxiliary steam chest 31 is provided, whichis located at one side of the steam chest 20 and is placed incommunication therewith through the medium of a duct 32, said ductextending below the partition wall 33 of the two chests andcommunicating with the chests through the seats 21 and 34 of the chests20 and 31, respectively, that end of the duct entering the auxiliarysteam chest 31, being covered by a flap valve 35, pivotally mounted uponthe seat 34 and the weight of the outer end of the valve beingsufficient to normally hold the same over the end of the duct, so thatas soon as the pressure of the expanded steam is removed, the valve willseat itself over the duct and prevent the return of the steam to thecylinder through the duct. The expanded steam, therefore, when passingthrough the port 28 and through the cavity 29 will enter the duct 32 andbe conveyed to the auxiliary chest 31, the pistons 15 and 17 movingtowards each other, serving to force the expanded steam through the portand duct.

The auxiliary chest 31 has slidably mounted therein a cut-off valve 36,which moves over the seat 34 and has pivotally secured to its centralportion, an auxiliary pitman 37, said pitman extending through asuitable bearing in the forward end of the auxiliary chest 31 and haspivotally secured to its extended end, an auxiliary, eccentric shaft 38,the forward free end of which is mounted upon an auxiliaryv eccentric39, said auxiliary eccentric being in turn fixed to the shaft 6.

'A pair of passages 40 and 41 are provided for the auxiliary steam chest31, said passages extending downwardly and outwardly from the seat 31 toopposite ends of the cylinder 2, and by properly arranging the cutoffvalve 36, one of the passages will be open, when the other passage isclosed, so that the expanded steam entering the auxiliary steam chestmay again return to the cylinder 2 through one end thereof, and in therear of the pistons 15 or 16, and, in this instance, the passage 40 isopen, thereby conducting the expanded steam from the auxiliary steamchest to the forward end of the cylinder and between the cylinder headand the piston 15, the force of the steam thus assisting in propellingthe pistons 15 and 16 through the cylinder. As this operation is takingplace, the piston 16 is traveling towards the rear end of the cylinder,which will result in forcing the exhaust steam in that end of thecylinder through the passage 41, from whence it enters an exhaust port42 communicating with the seat 34 of the auxiliary steam chest, thecut-off valve 36 being provided, in its lower surface, with a cavity 43,through which the exhaust steam is conveyed from the passage 41 into theexhaust port 42. v

The exhaust port 42 is provided with a branch port 44, which extendsbelow the wall 33 and enters the steam chest 20 and the bar 30,extending through the cavity, is so arranged that it will coversubstantially one-half of the branch port 44 when crate on the pistons,in the manner described.

In Fig. 7 of the drawings, the position of the parts of the engine areshown when the opposite stroke from that shown in Fig. 5 is being made,and, in this instance, the valve 22 has been moved to the opposite endof the steam chest 20, thereby closing the port 27 and opening the port26 the live steam being thereby directed between the pistons 15 and 17,this operation also closing the port 28 and opening a similar port 45 atthe opposite side ofan'd adjacent to the duct 32 and as the pistons 16and 17 are traveling towards each other, the expanded steam between saidpistons will be directed through the port 45 and into the auxiliarysteam chest through the duct. As the port 45 is in juxtaposition to theduct 32, the expanded steam will enter directly into the duct, therebynecessitating that the duct be partially closed to equalize the amountof the expanded steam entering the auxiliary chest with the differentstrokes of the valve 22 and by referring more particularly to Fig. 7, itwill be seen that the bar 30 will be partially disposed over the endofthe duct 32- and partially over the branch port 44, thereby reducing themouth of the duct when the expanded steam is entering through the port45 and equalizing the flow of the expanded steam through the duct andthe exhaust port, when the valve 22 is on its rearward stroke, with theflow from the port 28 through the cavity 29 and into the duct 32.

By referring more particularly to Fig. 8 of the drawings, it will alsobe seen that when the valve 22 is on its rearward stroke, the cutoffvalve 36 will move forwardly on its seat and connect the passage 40 withthe exhaust 42 and open the passage 41, thereby directing the expandedsteam from the auxiliary chest to the rear end of the cylinder 2 and inthe rear of the piston 16, thereby assisting in giving the pistons 15and 16 and arm 11 a forward stroke, while the piston 17 and arm 12 arebeing given a rearward stroke. If, when the engine stops, the partsshould be in the positions shown in Figs. 9 and 1.0 of the drawings,-itwill be seen that the valve 22 is in such position as to close both ofthe ports 26 and 27, so that when steam is directed into the chest 20,throughthe steam pipe 46, the steam cannot enter the cylinder, and inorder to cause the engine to start without employing manual labor torotate the driving shaft to uncover one of the inlet ports 26 or 27, avalve stem 47 is direct ed through a threaded opening extending throughthe side wall of the auxiliary steam chest 31 and has on its inner end atapered valve 48, which is adapted to enter a tapered bore, ,or seat 49in the wall 33, said bore extending entirely through said wall, so thatby turning the valve stem 47 until the tapered valve 48 is removed fromthe bore, the steam will pass from the steam chest 20 into the auxiliarychest 31 and thence through the opening 41 into the rear end of thecylinder, which will result in moving the pistons 15 and 16 a sufficientdistance to throw the cranks 7 and 8 off of the dead center, and at thesame time opening the port 26, when the engine will operate in the usualmanner, and as soon as the engine has started, the tapered valve 48 isreturned to the bore 49 and the flow of steam through the bore stopped,the stem being exteriorly threaded and readily operated through themedium of a hand-wheel 50. The valves 22 and 36 are so timed as to havea phase difference in their strokes, whereby when the parts ofthe engineare in the positions shown in Fig. 9, or on a dead center, the valve 36will have completed its rearward stroke and started on its forwardstroke, so that the opening 41 will be partially uncovered when thevalve 22 is in the position. shown, the phase difference of the strokesof the two pistons being thus arranged to allow the steam passingthrough the bore 49 to readily enter the opening 41 and accomplish theresult above described.

The pistons 15, 16 and 17 are provided on their peripheries with aplurality of packing rings 51, so that leakage of steam between saidpistons and the wall of the cylinder will be prevented, thereby dividingthe cylinder into four distinct steam chambers. It will thus be seenthat I have provided economical means for employing a multiplicity ofpistons with a single cylinder, and by arranging the pistons as shownand providing the auxiliary steam chest, I am enabled to employ theexpanded steam for additional driving purposes without increasing thenumber of cylinders or providing a separate expansion cylinder, and itwill further be seen that by providing a phase difference in the strokeof the valves in the main and auxiliary steam chests, the engine may bestarted from a dead center without employing manual labor in rotatingthe driving shaft. It will further be seen that by employing the samecylinder for utilizing the expanded steam, I am able to produce a verycompact form of engine and at the same time greatly enhance the drivingproperties of the same.

What I claim is:

1. In an engine of the class described, the

2. In an engine of the class described, the combination with a cylinder,a driving shaft and cranks 011 said driving shaft; of a plurality ofpistons in said cylinder two of which are fixed to move together and theother to move independently between the fixed pistons, means to connectsaid pistons to the cranks, means to direct steam between said pistonsand additional means to direct expanded steam into each end of saidcylinder and against the end piston.

3. In an engine of the class described, the combination with a cylinderand a driving shaft of a trio of pistons in said cylinder, one of whichis movable independently of the remaining pistons, means to operativelyconnect said pistons to the driving shaft, a steam chest above saidcylinder, a plurality of ports between said steam chest and cylinder,means to intermittently direct steam through said ports and between thetwo end pistons and the intermediate piston, an auxiliary chest, a ductbetween said first-mentioned chest and auxiliary chest to convey theexpanded steam into the auxiliary chest and means to alternately conveysaid expanded steam to opposite ends of the cylinder and into engagementwith the end pistons.

4. In an engine of the class described, the combination with a cylinder;of a pair of pistons adapted to reciprocate in opposite ends of saidcylinder, an independently movable piston between said end pistons, asteam chest for said cylinder, means to alternately direct live steam toopposite sides of the central piston, an auxiliary chest, means toconvey the expanded steam from opposite sides of the central piston tothe auxiliary chest and additional means to alternately direct theexpanded steam from the auxiliary chest to opposite ends of thecylinder.

5. The combination with a cylinder 3 of a pair of pistons fixed togetherand adapted to reciprocate in o posite ends of said cylinder, anindependenty movable piston between said end pistons, a steam chest forsaid cylinder, a port adjacent each end of said steam chest adapted todirect steam between the two end pistons and at opposite sides of theindependently movable iston and a valve in said steam chest adapter toalternately open and close said ports and means to convey the expandedsteam from between said pistons to opposite ends of the cylinder.

6. n an engine of the class described, the combination with a cylinder,a pair of pistons adapted to reci rocate in opposite ends of thecylinder an fixed with relation to each. other, an independently movablepiston between the end pistons and means to alternately direct steam toopposite sides of the independently movable piston; of an auxiliarysteam chest, means to convey the 'expanded steam from between thepistons to the auxiliary steam chest and additional means to alternatelydirect the expanded steam from the auxiliary steam chest to oppositeends of the cylinder.

v 7. In an engine of the class described, the combination with acylinder; of a plurality of pistons in said cylinder, a steam chest forsaid cylinder, ports connecting said. cylinder and steam chest, a valveadapted to alternately open and close said orts, an auxiliary steamchest at one side of t efirst mentioned steam chest, openings extendingfrom said auxiliary steam chest to opposite ends of the cylinder andmeans to direct live steam from the first mentioned steam chest to theauxiliary steam chest and into the cylinder, whereby the engine will bestarted from a dead center.

8. In an engine of the class described, the combination with a cylinderhaving a plurality of pistons therein; of a steam chest, a valveslidably mounted in said steam chest, ports connecting said cylinder andsteam chest, an auxiliary steam chest, a duct connecting said firstmentioned steam chest with the auxiliary steam chest, means to conveythe expanded steam from the cylinder to said duct, and a valve in theauxiliary chest adapted to automatically close said duct and prevent thereturn of the expanded steam to the first-mentioned steam chest.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ERVIN HARM KNAPP.

Witnesses:

GEO. W. RoYsE, J. W. MoINTYRE.

